Simplified sample treatment for the determination of total concentrations and chemical fractionation forms of Ca, Fe, Mg and Mn in soluble coffees

Food Chem. 2014 Nov 15:163:31-6. doi: 10.1016/j.foodchem.2014.04.073. Epub 2014 Apr 29.

Abstract

A simpler, and faster than wet digestion, sample treatment was proposed prior to determination of total concentrations for selected macro- (Ca, Mg) and microelements (Fe, Mn) in soluble coffees by flame atomic absorption spectrometry. Samples were dissolved in water and acidified with HNO3. Precision was in the range 1-4% and accuracy was better than 2.5%. The method was used in analysis of 18 soluble coffees available on the Polish market. Chemical fractionation patterns for Ca, Fe, Mg and Mn in soluble coffees, as consumed, using a two-column solid-phase extraction method, determined Ca, Mg and Mn were present predominantly as cations (80-93% of total content). This suggests these elements are likely to be highly bioaccessible.

Keywords: Calcium; Direct analysis; Flame atomic absorption spectrometry; Iron; Magnesium; Manganese; Solid phase extraction; Soluble coffee.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / analysis*
  • Coffee / chemistry*
  • Iron / analysis*
  • Magnesium / analysis*
  • Manganese / analysis*
  • Solid Phase Extraction
  • Spectrophotometry, Atomic / methods

Substances

  • Coffee
  • Manganese
  • Iron
  • Magnesium
  • Calcium